Preliminary Diffusive Clearance of Silicon Nanopore Membranes in a Parallel Plate Configuration for Renal Replacement Therapy

Kim, Steven; Heller, J. Alex; Iqbal, Zohora; Kant, Rishi; Kim, Eun Jung; Durack, Jeremy C.; Saeed, Maythem; Do, Loi; Hetts, Steven W.; Wilson, Mark; Brakeman, Paul; Fissell, William H.; Roy, Shuvo

doi:10.1097/mat.0000000000000311

Cited by 7 publications

(7 citation statements)

References 18 publications

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“…Tunneled catheters were placed in the carotid artery and jugular vein of a 55 kg Yorkshire female pig, and a closed external circuitry was set up. A custom designed, flow path optimized titanium housing containing separated blood flow chambers, 58 each holding 18 1 Â 1 cm 2 solid pSBMA-silicon chips was utilized for ex vivo blood flow experiments. Blood flowed from the carotid artery through Masterfelx, Tygon E-LFL Tubing (L/S 25, 4.8 mm inner diameter from Cole-Parmer) to the extracorporeal device, then back through Tygon tubing to the catheter connected to the jugular vein.…”

Section: Extracorporeal Studymentioning

confidence: 99%

In vitro and in vivo hemocompatibility assessment of ultrathin sulfobetaine polymer coatings for silicon-based implants

et al. 2019

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Highly uniform silicon nanopore membranes were developed for applications in implantable bioartificial organs. A robust, readily scalable, non-fouling surface coating is required to enhance silicon nanopore membrane hemocompatibility. However, the coating must be ultrathin to keep the nanopores from occluding. Recently, zwitterionic brush polymers have demonstrated significantly lower fouling under biological conditions. In this study, we explore ultrathin zwitterionic poly(sulfobetaine methacrylate) (pSBMA) surface coating at sub-5 nm thickness. Membrane hydraulic permeability was measured before and after surface modification of silicon nanopore membranes, and pores were found to be patent and in agreement with coating thickness measurements. Coating stability was analyzed under biological shear as well as under blood flow in vitro and in vivo. Following exposure to shear over 24 h, coatings were characterized via X-ray photoelectron spectroscopy, goniometry, and ellipsometry, and found to survive biological shear. In vitro blood experiments with fresh human blood as well as in vivo 7-day and 26-day implants in a porcine model demonstrate minimal platelet adhesion and activation with pSBMA surface modification compared to unmodified silicon exposed to fresh human blood in vitro. These results demonstrate that ultrathin pSBMA surface modification is a viable choice for application in blood contacting implants with critical nanoscale features.

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Section: Extracorporeal Studymentioning

confidence: 99%

In vitro and in vivo hemocompatibility assessment of ultrathin sulfobetaine polymer coatings for silicon-based implants

et al. 2019

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“…The fabrication of the SμM‐PDMS membrane is based on prior work in this lab on silicon nanopore membranes, with adaptations specific to this project . Briefly, the prior work describes a process by which controlled growth of silicon dioxide produces arrays of sub‐100 nm rectangular pores within silicon wafers (Fig.…”

Section: Methodsmentioning

confidence: 99%

Silicon Micropore‐Based Parallel Plate Membrane Oxygenator

et al. 2017

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Extracorporeal membrane oxygenation (ECMO) is a life support system that circulates the blood through an oxygenating system to temporarily (days to months) support heart or lung function during cardiopulmonary failure until organ recovery or replacement. Currently, the need for high levels of systemic anticoagulation and the risk for bleeding are main drawbacks of ECMO that can be addressed with a redesigned ECMO system. Our lab has developed an approach using microelectromechanical systems (MEMS) fabrication techniques to create novel gas exchange membranes consisting of a rigid silicon micropore membrane (SμM) support structure bonded to a thin film of gas-permeable polydimethylsiloxane (PDMS). This study details the fabrication process to create silicon membranes with highly uniform micropores that have a high level of pattern fidelity. The oxygen transport across these membranes was tested in a simple water-based bench-top set-up as well in a porcine in vivo model. It was determined that the mass transfer coefficient for the system using SµM-PDMS membranes was 3.03 ± 0.42 mL O min m cm Hg with pure water and 1.71 ± 1.03 mL O min m cm Hg with blood. An analytic model to predict gas transport was developed using data from the bench-top experiments and validated with in vivo testing. This was a proof of concept study showing adequate oxygen transport across a parallel plate SµM-PDMS membrane when used as a membrane oxygenator. This work establishes the tools and the equipoise to develop future generations of silicon micropore membrane oxygenators.

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“…The hemofiltration unit is constructed from biocompatible silicon nanopore membranes, which exhibit high flux and high selectivity such that cardiac perfusion pressure is sufficient enough to drive blood flow without need for battery or electrical power. Various components of the implantable artificial kidney are being evaluated via a series of preclinical studies (18,(49)(50)(51)(52)(53). Membranes configured in a parallel-plate hemofilter format were implanted in six dogs that received only antithrombotic therapy (acetylsalicylic acid) (18).…”

Section: Implantable Kidney Replacement Therapymentioning

confidence: 99%

Ambulatory Hemodialysis-Technology Landscape and Potential for Patient-Centered Treatment

Hojs¹,

Fissell²,

Roy³

2019

CJASN

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CKD is a worldwide health problem and the number of patients requiring kidney replacement therapy is rising. In the United States, most patients with ESKD rely on in-center hemodialysis, which is burdensome and does not provide the same long-term benefits as kidney transplantation. Intensive hemodialysis treatments have demonstrated improved clinical outcomes, but its wider adoption is limited by equipment complexity and patient apprehension. Ambulatory devices for hemodialysis offer the potential for self-care treatment outside the clinical setting as well as frequent and prolonged sessions. This article explains the motivation for ambulatory hemodialysis and provides an overview of the necessary features of key technologies that will be the basis for new wearable and implantable devices. Early work by pioneers of hemodialysis is described followed by recent experience using a wearable unit on patients. Finally, ongoing efforts to develop an implantable device for kidney replacement and its potential for implantable hemodialysis are presented.

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Preliminary Diffusive Clearance of Silicon Nanopore Membranes in a Parallel Plate Configuration for Renal Replacement Therapy

Cited by 7 publications

References 18 publications

In vitro and in vivo hemocompatibility assessment of ultrathin sulfobetaine polymer coatings for silicon-based implants

In vitro and in vivo hemocompatibility assessment of ultrathin sulfobetaine polymer coatings for silicon-based implants

Silicon Micropore‐Based Parallel Plate Membrane Oxygenator

Ambulatory Hemodialysis-Technology Landscape and Potential for Patient-Centered Treatment

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